Rack: Knobs and faders jump unexpectedly when dragging

[rubyglow]

Operating system: MacOS 10.12.6 (Sierra)
GPU: NVIDIA GeForce GTX 780M (4GB)
Machine: iMac late 2013, with plenty of beef
Rack version: v1.1.4

This is a re-opening of #1367 which had a fix for it in Rack 1.1.4 but unfortunately is not fixed for me. The same issue persists.

Summary:
When dragging knobs or faders, to adjust their value and position, their position sometimes suddenly move to a completely different position, than the one you were dragging it to.

Details:

This happens both for knobs and faders.
How often? Difficult to say exactly but I estimate around 5% of the time I'm adjusting a knob/fader.
When? I cannot correlate it with any external factors, it just happens sporadically and spontaneously.

This issue happens only during the dragging of a knob or a fader, not before or after. To be exact - a dragging operation:
1) Starts with clicking the left mouse button on a knob/fader.
2) Whilst holding down the mouse button, moving the mouse to the desired location.
3) Ends with releasing the left mouse button.

The issue happens in phase 2, during the dragging, whilst the left mouse button is held down. Not before 1 and not after 3. It can happen a split second after phase 1 or a split second before phase 3 or in the middle of phase 2.

The effect of the issue, how it's perceived, is, that during the dragging of a knob/fader to it's new position, it's like an invisible and forceful hand reaches up from the back of the screen, and instantly yanks the knob/fader to a completely different position than the position you were at. The "yanking" is instantaneous, it's not a gradual process. The position it is yanked to, seems to be mostly the extremes of either hard left/bottom or hard right/top, or right in the middle, the default postion, but other positions can occur.

It only happens in Rack, not in any other programs.

I'll be happy to answer further detailed questions, and also to run debug builds if needed. Thanks for looking at this Andrew!

All the best,
Lars Bjerregaard

[jonheal]

It is _very_ rare for me now, but yesterday, I experienced a knob jump on a Vult filter. I am certain I did not double-click the knob in this instance. The module was in the top half of the screen and the value jumped from about 60% to 100% when I clicked it.

But like I said, it doesn't happen too often anymore, but since it does seem to still happen on occasion, I am guessing Ben's fix addressed a symptom, but not the root cause of this problem.

Still — way better than it was, At least for me.

[ContemporaryInsanity]

Rare here too now, but still happens occasionally, the pan knobs on VCV Console were jumping yesterday but seem fine this morning. V1.1.5.

[Ananda6262]

This happens when I am not very deliberate with my mouse click...

Win 10
i7-6700HQ
GTX-960m

[rubyglow]

Please, everyone chiming in, if you could please state your OS and OS version, thanks a bunch!

[ContemporaryInsanity]

Sorry, linux mint 19.1 4.15.0-64-lowlatency.
Intel i7-4790k, RX570 gfx.

[vooh]

I can confirm the issue in Win10\Win7. I have been experiencing it since the 1.0.0 version. This issue has never been noticed on 0.6.X versions.

checked on 2 PCs

1. Win7x64, core-i7 2600k, 16GB, GTX 1060ti
2. Win10x64 core-i5 8300H, 16GB, GTX 1050

[fractalgee]

MacOS X 10.11.6, Rack 1.1.5

still happening randomly, turning off lock cursor when dragging does not seem to have any affect on this....

[AndrewBelt]

turning off lock cursor when dragging does not seem to have any affect on this

That's interesting. Can anyone confirm?

[vooh]

yep, no effect

[fractalgee]

I can make this happen regardless of mouse and no driver used for either, just the built-in in MacOS X 10.11.6. No other app shows this issue, so not sure what to make of it. nanovg oddity? oh, should mention I have frame rate at 15, but that should either cause it often or never not sometimes. I can go for an hour without, then happens twice in 15 minutes then disappears again....